Packet-based communication systems allow the user of a device, such as a personal computer, to communicate across a computer network such as the Internet. Packet-based communications systems include voice over internet protocol (“VoIP”) communication systems and instant messaging (“IM”) systems. These systems are beneficial to the user as they are often of significantly lower cost than fixed line or mobile networks. This may particularly be the case for long-distance communication. To use a VoIP or IM system, the user must install and execute client software on their device. The client software provides the VoIP or IM connections as well as other functions such as registration and authentication. In addition to voice communication, the client may also provide further features such as video calling.
One type of packet-based communication system uses a peer-to-peer (“P2P”) topology built on proprietary protocols. To enable access to a peer-to-peer system, the user must execute P2P client software provided by a P2P software provider on their computer, and register with the P2P system. When the user registers with the P2P system the client software is provided with a digital certificate from a server. Once the client software has been provided with the certificate, communication can subsequently be set up and routed between users of the P2P system without the further use of a server. In particular, the users can establish their own communication routes through the P2P system based on the exchange of one or more digital certificates (or user identity certificates, “UIC”), which enable access to the P2P system. The exchange of the digital certificates between users provides proof of the user's identities and that they are suitably authorised and authenticated in the P2P system. Therefore, the presentation of digital certificates provides trust in the identity of the user. It is therefore a characteristic of peer-to-peer communication that the communication is not routed using a server but directly from end-user to end-user. Further details on such a P2P system are disclosed in WO 2005/009019.
In contrast to traditional communication systems such as fixed-line or mobile networks, the communication client for a packet-based communication client has a flexible, rich graphical user interface. The graphical user interface is displayed to the user on a display of the personal computer, and permits the communication client to present a large number of features and options to the user. However, it is difficult for the provider of the client software to inform the user of these features in a timely and non-intrusive manner.